From: Mark Wooding <mdw@distorted.org.uk>
Date: Tue, 11 Apr 2006 17:06:28 +0000 (+0100)
Subject: safely: Blank lines make code easier to read.
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/lisp/commitdiff_plain/5e04ac396871d9b15a4cbcdb7de9084b650176f0?ds=sidebyside

safely: Blank lines make code easier to read.
---

diff --git a/safely.lisp b/safely.lisp
index 6153060..5eddef3 100644
--- a/safely.lisp
+++ b/safely.lisp
@@ -34,12 +34,15 @@ (defstruct (safely (:predicate safelyp))
   "Stores information about how to commit or undo safe writes."
   (streams nil)
   (trail nil))
+
 (defun safely-close (safe stream)
   "Make sure that STREAM is closed when SAFE is finished."
   (push stream (safely-streams safe)))
+
 (defun safely-delete-file (safe file)
   "Delete FILE when SAFE is committed."
   (push `(:delete ,file ,(fresh-file-name file "del")) (safely-trail safe)))
+
 (defun fresh-file-name (base tag)
   "Return a fresh file name constructed from BASE and TAG in the current
 directory.  Do not assume that this filename will be good by the time you try
@@ -47,6 +50,7 @@ (defun fresh-file-name (base tag)
   (let ((name (format nil "~A.~A-~X"
 		      base tag (random most-positive-fixnum))))
     (if (probe-file name) (fresh-file-name base tag) name)))
+
 (defun safely-open-output-stream (safe file &rest open-args)
   "Create an output stream which will be named FILE when SAFE is committed.
 Other OPEN-ARGS are passed to open."
@@ -60,15 +64,18 @@ (defun safely-open-output-stream (safe file &rest open-args)
     (push `(:shunt ,new ,file ,(fresh-file-name file "old"))
 	  (safely-trail safe))
     stream))
+
 (defun delete-file-without-moaning (file)
   "Delete the FILE, ignoring errors."
   (when (probe-file file)
     (unix-try unlink file)))
+
 (defun rename-file-without-moaning (old new)
   "Rename OLD to NEW, ignoring errors, and without doing any stupid name
 mangling."
   (when (probe-file old)
     (unix-try rename old new)))
+
 (defun safely-unwind (trail)
   "Roll back the TRAIL of operations."
   (dolist (job trail)
@@ -84,10 +91,12 @@ (defun safely-unwind (trail)
       (:revert (destructuring-bind (tag old new) job
 		 (declare (ignore tag))
 		 (rename-file-without-moaning old new))))))
+
 (defun safely-reset (safe)
   "Reset SAFE to its initial state."
   (setf (safely-streams safe) nil)
   (setf (safely-trail safe) nil))
+
 (defun safely-bail (safe)
   "Abort the operations in SAFE, unwinding all the things that have been
 done.  Streams are closed, new files are removed."
@@ -95,6 +104,7 @@ (defun safely-bail (safe)
     (close stream :abort t))
   (safely-unwind (safely-trail safe))
   (safely-reset safe))
+
 (defun safely-commit (safe)
   "Commit SAFE.  The files deleted by safely-delete-file are deleted; the
 files created by safely-open-output-stream are renamed over the old versions,
@@ -132,6 +142,7 @@ (defun safely-commit (safe)
       (safely-unwind revert)
       (safely-unwind cleanup)
       (safely-reset safe))))
+
 (defmacro safely ((safe &key) &body body)
   "Do stuff within the BODY safely.  If BODY completes without errors, the
 SAFE is committed; otherwise it's bailed."
@@ -143,6 +154,7 @@ (defmacro safely ((safe &key) &body body)
 	   (setf ,safe nil))
        (when ,safe
 	 (safely-bail ,safe)))))
+
 (defmacro safely-writing ((stream file &rest open-args) &body body)
   "Simple macro for writing a single file safely.  STREAM is opened onto a
 temporary file, and if BODY completes, it is renamed to FILE."